Add migrate-integration and document-api-integration skills (#5442)

* Add migrate-integration and document-api-integration skills

- New skill: migrate-integration - guides migration of reconcile/
  integrations to qontract-api architecture (6 phases: discovery,
  utils, server-side, external endpoints, client-side, tests+docs)
- New skill: document-api-integration - converted from command to
  skill for auto-triggering support
- Simplified document-api-integration command to delegate to skill
- New command: /migrate-integration as shortcut for the skill

* remove slash cmds

Author: chassing

.claude/commands/document-api-integration.md

@@ -0,0 +1,54 @@
+---
+name: document-api-integration
+description: Generate comprehensive documentation for a qontract-api integration. Use this skill when a new integration has been created or migrated to qontract-api and needs documentation, or when someone asks to document an integration. Triggers on requests mentioning integration documentation, documenting API integrations, or after completing a migration with /migrate-integration.
+---
+
+# Document qontract-api Integration
+
+Analyze an existing qontract-api integration and generate documentation following the standard template at `docs/integrations/template.md`.
+
+## Input
+
+Integration name (e.g., "slack-usergroups"). If not provided, ask for it.
+
+Validate the integration exists at `qontract_api/qontract_api/integrations/<name>/` before proceeding.
+
+## Workflow
+
+1. **Read the template** from `docs/integrations/template.md`
+
+2. **Analyze the integration** by reading:
+   - `qontract_api/qontract_api/integrations/<name>/models.py` - Request/Response/Action models
+   - `qontract_api/qontract_api/integrations/<name>/service.py` - Business logic
+   - `qontract_api/qontract_api/integrations/<name>/router.py` - API endpoints
+   - `qontract_api/qontract_api/integrations/<name>/tasks.py` - Celery tasks
+   - Other files in the integration directory (factory, client, etc.)
+   - `reconcile/<name>_api.py` or `reconcile/<name>_api/` - Client integration
+   - Related ADRs referenced in docstrings/comments
+
+3. **Extract information** for each template section:
+   - **Features**: What it does, actions it can perform, resources it manages
+   - **API Endpoints**: POST/GET paths, parameters, responses
+   - **Models**: Pydantic structure, key fields, validation rules (dry_run default=True)
+   - **Actions**: All action types from discriminated union models
+   - **Architecture**: Client-side vs server-side responsibilities
+   - **Limits/Constraints**: Safety features, rate limits, cache TTLs, managed resources
+   - **Required Components**: Vault secrets, external APIs, environment variables
+
+4. **Generate documentation** using the template structure exactly. Fill all sections. Mark non-applicable sections as "[Not applicable for this integration]".
+
+5. **Show summary** to user before writing:
+   - API path, features count, action types, external APIs, requirements
+
+6. **Write files** after confirmation:
+   - Create `docs/integrations/<name>.md`
+   - Update `docs/integrations/README.md` with link in alphabetical order
+
+## Guidelines
+
+- Follow the template structure from `docs/integrations/template.md` exactly
+- Extract information from actual code, not assumptions
+- Reference relevant ADRs
+- Include practical usage examples (curl commands, CLI)
+- Emphasize dry_run defaults and safety features
+- Set Last Updated date to today